A MEMS (Micro-Electro-Mechanical-System) device is a micro-sized mechanical structure having electrical circuitry fabricated together with the device by various microfabrication processes mostly derived from integrated circuit fabrication methods. The developments in the field of microelectromechanical systems (MEMS) allow for the bulk production of microelectromechanical mirrors and mirror arrays that can be used in all-optical cross connect switches, 1×N, N×N optical switches, attenuators etc. A number of microelectromechanical mirror arrays have already been built using MEMS production processes and techniques. These arrays have designs that fall into approximately three design categories. A desirable component of many MEMS devices is an actuator that provides for either tip-tilt (2 degrees of freedom) or tip-tilt-piston (3 degrees of freedom) actuation.
Utilizing gimbaled structures is the most common method of implementing two-axis (two degrees of freedom, 2 DoF) rotation, although packaging-based methods are utilized as well. However, to implement 2 DoF gimbaled micromirrors without cross talk between driving voltages, electrical isolation and mechanical coupling is necessary. Backfilling of isolation trenches by depositing an additional dielectric layer and chemical mechanical polishing (CMP) has been used to achieve the electrically isolated mechanical coupling. However, the additional deposition and CMP steps significantly increase complexity and cost. Another viable method is to leave part of the handle wafer unetched beneath the gimbal structure. In all cases, complex fabrication has been required, and relatively low frequencies have been achieved due to the gimbals' slow outer axis. In applications where high speed static scanning is required the previous methods do not provide adequate solutions.